Think I should call?

Not sure if Im just being a paranoid new mom or not. LO had just gotten over a cold a week or two before his wellness appt which was Nov. 7th. I told the Dr and he said he looked fine. However, lately LO sounds like he needs to clear his throat and sometimes I can feel rumblings in his chest as if he has a build up of phlegm. Maybe its the way he is eating the formula? Or allergies? I would think it would be too late for any serious repercussions of his cold like pneumonia or bronchitis, right? The rim of his eyes have been getting a little red on occasion and recently I noticed some sneezing/coughing.

Am I being a nervous nelly? Can they even test for allergies yet? LO is only a little over 2 months.